"Blame me for this, not my family," Remy, 35, told the court moments before being led away in shackles to begin the mandatory life sentence that comes with a first-degree murder conviction.

Remy on Tuesday changed his plea to guilty to charges of first-degree murder, assault and battery with a dangerous weapon, assault with a dangerous weapon, assault and battery and violating a restraining order in connection with the 27-year-old's death.

"I'm the bad apple," Remy told the court Tuesday. "I know my family would rather have me dead, not her."

According to Assistant District Attorney Lisa McGovern, the Aug. 15 attack began inside the couple's Stearns Hill Road apartment before spilling out onto a patio, where Martel screamed for help.

McGovern said Remy continued to stab and slash the woman with a knife as neighbors tried to pull him away. At the end of the attack, Remy removed his blue tank top, put it over her face and walked away, witnesses said.

Martel was pronounced dead a short time later. Remy was arrested at the scene.

Remy showed no emotion Tuesday as McGovern read a detailed account from witnesses of Martel's last moments. When asked if he committed the acts outlined in the statement, Remy replied, "Yes, I did."

Remy said on the night of Aug. 15, Martel had a knife and threatened to take away his daughter.

"I always told Jen she could leave, but do not threaten me with my daughter," Remy said. "That night Jen had a knife in her hand and threatened me with my daughter. So I killed her."

Remy said he had never been treated for mental health issues, but was currently taking Zoloft for depression.

"Jared Remy took full responsibility for the death of his fiancee, Jennifer Martel. He stood up in the courtroom, answered all the judge's questions and took full responsibility," defense attorney Ed Ryan said.

In a statement from Martel's parents, Brian Sr. and Patty, read by Alec Zadek, the family said they have been living a nightmare.

"We still dream about it. The drive to keep living is gone. The only thing keeping us together, besides God, is our children and grandchildren," Zadek read.

"When I lost my sister, I lost a part of me," Martel's brother, Brian Jr., wrote in a statement that was read in court.

Ryan said Remy specifically asked that his father, former Red Sox second-basemen and current broadcaster Jerry Remy; mother, Phoebe; and siblings not attend Tuesday's proceedings.

The Martels urged other families not to ignore the warning signs of domestic abuse.

"Our family's world will never be the same. There will always be sadness. When she died, a part of us died, too," Zadek read.

Two days before her death, Remy was charged with assault and battery after allegedly pushing Martel into a mirror. Remy was released on personal recognizance on Aug. 14.

Martel got an emergency temporary restraining order after the incident.

The Martel and Remy families reached a custody agreement for the couple's 5-year-old daughter Arianna in March. The girl is living with Martel's brother, Brian Jr. and his family.

Remy's parents 'raked over the coals' over son's killing

After the proceeding, Remy's attorney, Ed Ryan, said his client asked that his family not be present in court.

"He feels very strongly that his parents have been raked over the coals, unnecessarily all throughout this case," Ryan said. "Pheobe and Jerry Remy did not kill Jennifer Martel."

Ryan said his parents loved Martel like a daughter.

"Just because a child goes off the rails it is not the occasion to blame their parents," Ryan said, adding that all too often parents are blamed for the crimes of their children.

"I've been prosecuting and defending cases for 37 years, and quite frankly, the assault on the Remys as parents has shocked me," Ryan said. "Jared Remy stood up in court and took full responsibility for what he did."

Timeline: Jared Remy admits killing girlfriend Jennifer Martel

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The son of famed Boston Red Sox broadcaster Jerry Remy pleaded guilty to stabbing his girlfriend to death in their Waltham apartment while their young daughter was home.